Photocomposing machine

ABSTRACT

A light-deflection system which is adapted to function as a photocomposing system is described. A laser light beam is deflected to any one of a group of locations along a character matrix array in order to illuminate a pre-selected character which is to be projected onto a light-sensitive surface such as a film. After selection, the character-bearing light beam is directed to a desired position on the film by a group of crystal deflectors in order to form lines of composition on the film. Also disclosed is a system for automatically positioning characters on a line after a point size change, a white space reduction circuit, &#39;&#39;&#39;&#39;coarse&#39;&#39;&#39;&#39; and &#39;&#39;&#39;&#39;fine&#39;&#39;&#39;&#39; character positioning or spacing, a light beam deflection system, and an embodiment of the optical leverage concept in which the character size-changing mechanism is positioned in the optical path between the character image deflection system and the film, so that the spacing of the characters relative to each other is not affected by a change in point size, since all provisions for character spacing are completed before the character images pass through the sizechanging mechanism.

United StatesPatent Moyroud 1151 3,703,138 1451 Nov. 21, 1972 [54] PHOTOCOMPOSING MACHINE [72] Inventor: Louis M. Moyroud, c/o Photon, Inc., 355 Middlesex Avenue, Wilmington, Mass. 01887 23, 1967, Pat. No. 3,512,462, and Ser. No.

827,128, May 21, 1969.

1521 05.121. .9s/4.sn

[5|] Int. Cl. ..B4lb 21/26 [58] Field of Search ..95/4.5 R; 350/150; 355/66, 355/40; 346/107 R [56] References Cited UNITED STATES PATENTS 3,532,033 10/1970 Chang ..95/4.5

3,540,794 11/1970 Kosanke et a1. ..350/l50 3,353,894 11/1967 Harris ..95/4.5 X

3,588,820 6/1971 7 Cobb et a1 ..346/107 R Primary Examiner-Robert P. Greiner Attorney-William D. OReilly [57] ABSTRACT A light-deflection system which is adapted to function as a photocomposing'system is described. A laser light beam is deflected to any one of a group of locations along a character matrix array in order to illuminate a pre-selected character which is to be projected onto a light-sensitive surface such as a film. After selection,

the character-bearing light beam is directed to a desired position on the film by a group of crystal deflectors in order to form lines of composition on the film. Also disclosed is a system for automatically positioning characters on a line after a-point size change, a white space reduction circuit, coarse and fine character positioning or spacing, a light beam deflection system, and an embodiment of the optical leverage concept in which the character size-changing mechanism is positioned in the optical path between the character image deflection system and the film, so that the spacing of the characters relative to each other is not affected by a change in point size, since all provisions for character spacing are completed before the character images pass through the size-changing mechanism.

12 Claims, 32 Drawing Figures llllllllll Illlllllll SHEET 0101 12 INVENTOR LOUIS M. 'MOYROUD PATENTED H 21 1972 3. 7 O3. 138

' SHEET OEUF 12 INVENTOR H 2 LOUIS M. MOYROUD ATTORNEY PA'TENTEnuuvzl 1912 3.703.138

' sum 030F12 FIG. 3

8 lNVENTOR LOUIS M. MOYROUD ATTORNEY PATENTEnnuvel I972 SHEET OSUF 12 FIG. 6

II I

INVENTOR LOUIS M MOYROUD lllllIlI 7 50299 W ATTORNEY? PATENTEMuveusvz v 3.703.138 sum USUF 12 mum FIG 24 INVENTOR LOUIS M. MOYROUD ATTORNEY PATENTEDNHVZI I972 sum 10 0F 12 209 zso 2H 212 POINT TYPE SIZE FACE STORED CORRECTION EXPOSURE VALUES CONTROL 330 329 332 lNVENTOR SPA NG LOUIS M. MOYROUD ACCUMULATED WIDTH C! VALUE SUBTRACTOR CIRCUITS a I FIG. 2s 5 ATTORNEY PATENTEDNBYZHBY? 3,703,138

SHEET llUF 12 l 731 FIG. 27

' FIG. 32

LINE STORAGE SEQUENCE JUSTIF. AND CONTROL c RcuITs CONTROL 36| 359 356 MARG'N WIDTH IDENTITY ggfigg TABLES CODES I 362 I V i 360 FuNcTIbNs figffigfl? ADDER- ACCUMULATOR RANK VALUES SUBTRACT. TABLE I 366 364 357 NE SEGMENT EXPOSURE BNTROL ccT. ADDER LIGHT DEFLECI DISPLACEMENT RESET "vAI uE REGISTER COARSE FINE DEFLECT. CCT. DEFLECT. act

FLASH CONTROL INVENTOR FIG. 3| LOUIS M.MOYROUD CALL FOR NEXT CHAR.

24 3 (WQ/f ATTORNEY Ii PIIOTOCOMPOSING MACHINE The present invention is a continuation-in-part of U.S. Ser. No. 617,912 filed Feb. 23, 1967, now U.S. Pat. No. 3,512,462 and U.S. Ser. No. 827,128 filed May 21, 1969. Each of the foregoing disclosures are expressly incorporated by reference herein.

BACKGROUND AND BRIEF DESCRIPTION OF THE INVENTION This invention relates to an improvement on machines using high speed light deflection means to produce lines of characters of various sizes and various widths on a photoreceptor.

In the prior art characters were arranged on a stationary matrix in columns and row formation. Character-bearing light beams had to be deflected along two directions at right angles. Characters of different widths were generally brought to a common axis and then deflected to a pre-selected location on a film. Also light deflection crystals of sizes so large as to be impractical had to be utilized for the large amount of light deflection necessary for the production of reasonably long lines.

According to the present invention characters of various widths necessary to compose a line and comprising generally all the letters of the alphabet are located on a matrix strip and character-bearing light beams are deflected in one plane only to locate preselected characters on the line to be composed. This is achieved by controlling the character positioning light deflection system in accordance with the location of each master character on the matrix plate and the accumulated width of other characters of the line, basically as explained and described in U.S. Pat. No. 3,188,929, which is expressly incorporated by reference herein.

According to another feature of the invention the positioning of characters along a line is achieved in two steps by coarse and fine positioning.

According to another feature of the invention the coarse light deflection means includes means to deflect light in a direction perpendicular to the direction of the composed line together with reflecting surface making it possible to considerably reduce the size and cost of the static deflectors required in previous machines.

According to another feature of the invention means are provided for rapid change of point sizes.

According to yet another feature of the invention automatic means are provided for locating characters at pre-determined location on the photoreceptor regardless of magnification ratio. The means include, but are not limited to, the automatic positioning of characters evenly with the left hand margin or centered on the page.

In a modified version of the invention the character matrix moves past an exposure station for the purpose of selectively illuminating characters.

Other features of the invention include novel illumination and character positioning means with means to variably space characters in accordance with their design and sizes in a non-proportional way so that the amount of white space between characters is made a function of the projection magnification of said characters for a given style or type face.

The foregoing invention will be more fully described in the detailed description which follows, in which:

FIG. 1 is a schematic representation of a preferred embodiment of the composing machine;

FIG. 2 represents the combined character selection and positioning system;

FIG. 3 schematically represents the selective illumination system of the character matrix;

FIG. 4 is an alternative light beam deflection unit;

FIG. 5 represents a character matrix strip;

FIG. 6 is a schematic representation of another embodiment of the composing machine;

FIG. 7 is a cross-section of FIG. 1;

FIG. 8 is a schematic representation of a preferred light deflection system;

FIG. 9 represents an embodiment of the line segment projection unit of the machine;

FIG. 10 is a cross-section of FIG. 9;

FIG. 1 1 represents a projection lens employed in the machine;

FIG. 12 represents a portion of a lens turret in crosssection;

FIG. 13 represents alternative means for the high speed selection of different lenses;

FIG. 14 represents a portion of the lens turret of the machine;

FIG. 15 represents the rank value of an alphabet in one embodiment of the invention;

FIG. 16 is a table representing the system utilized to select and spacecharacters for the composition of a line of text;

FIG. 17 represents a variant of the projection system for different character sizes;

FIG. 18 shows schematically the variation of character positions on the film for various magnification ratios in a preferred optical system;

FIG. 19 is a schematic representation of another variant of the projection system of the machine illustrating the character placement correction in accordance with various magnification ratios in order to achieve even margins;

FIG. 20 is a block diagram illustrating one way to implement the correction shown in FIG. 19;

FIG. 21 is another schematic representation of a variant of the projection system illustrating the automatic centering of lines for various magnifications;

FIG. 22 is a block diagram showing one way of implementing the automatic centering of lines as per FIG. 21;

FIG. 23 is a schematic representation of a variant of the invention including a continuously moving matrix;

FIG. 24 represents in more detail the showing of FIG. 23; 1

FIG. 25 represents a portion of the mechanism of FIG. 24;

FIG. 26 diagrammatically depicts a multiple light source illuminating system that can be utilized in the machine;

FIG. 27 is a schematic representation in cross-section, of a matrix unit;

FIG. 28 is a block diagram representing the automatic character spacing correction for inter-character space reduction depending on style and the sizes of character images;

FIG. 29 represents the relative position of a letter in different line segments relative to an example of composition;

FIG. 30 is a table representing the values utilized to I v select and position characters of different sizes;

FIG. 31 is a block diagram illustrating the general operation of the machine for character selection and positioning; and

FIG. 32 represents a variation of the embodiment of FIG. 23.

DETAILED DESCRIPTION OF THE INVENTION Referring to the drawings, in FIG. 1, blocks 2 and 4 represent light sources capable of producing flashes of monochromatic collimated and polarized light, such as a pulsed laser or a continuous laser associated with an electrooptic shutter. The light beams emerging from boxes 2 and 4 shown at 3 and 5 have a cross-section large enough to cover the matrix characters. The light beams are deflected by blocks 6 and 8 respectively to emerge from said blocks along one of a plurality of light paths shown at 50 and 52. The deflected light beam passes first through a selected character of matrix array 10 and then through an optical merging system comprising reflecting face 12 and semireflecting face 14 to emerge in the form of a character-bearing light beam along one of the paths shown at 54. The selected emerging beam then enters a coarse selecting and spacing deflector block 16, from which it emerges to enter the fine spacing deflector 18 see FIG. 6 of the drawings, after which the character-bearing beam emerges in the bundle area 56. The beam is further deflected by a series of deflectors to reach a pre-determined line segment of the line to be composed, as will be more fully explained later.

FIG. 5 depicts a matrix strip 140, which may consist of a narrow glass plate bearing transparent character shapes on an opaque background. A complete transparent alphabet is preferably located along a single row 141. Other character rows (preferably comprising special symbols etc.) may be located on other levels as shown at 143. In a preferred embodiment of the invention there is only one line of master characters in photographic position at any time in the machine. Passage from one row to another row may be accomplished by mechanical or optical means in response to a face shift command from the control circuit of the machine. In a preferred arrangement, a black gap 145 is located at the center of the character row for the purpose of enabling optical merging of the half-rows by merging means 12-14 (see FIG. 1). Different master character strips are accurately located on a movable frame 182 by the use of pins 147 engaging locating holes, as explained in U.S. Pat. No. 3,188,929. Frame 182 is moved up and down by mechanical means (not shown) to bring the selected matrix strip into projection position.

The selective illumination of a pre-determined character can be accomplished as shown in FIG. 3. In this Figure, beam 3 of narrow cross-section emerging from light source 2 passes through the electro-optic crystal 1 10, provided with transparent electrodes. As is well known in the art, depending on the presence of a potential across the electro-optic crystal, the emerging light beam will be polarized in one plane or another at right angles thereto, and after passing through birefringent crystal 100 it will emerge either along path 7 (ordinary ray) or path 9 (extraordinary ray). An important aspect of a feature of the invention resides in the use of birefringent crystals of relatively small thickness to achieve large beam deflections. Thus, a crystal of thickness 98, (see FIG. 3) which is designed to separate the E and O rays by a small distance is associated with a movable mirror system consisting of reflecting roof 120 and mirrors 121 and 122 in order to produce any desired separation of the light beams. Rays 7 or 9, after passing through electro-optlc crystal 112 and birefringent crystal 102, are further divided by mirror systems 123-128-27 or 124-125-126, depending on the selection of rays 7 or 9 respectively.

As can be seen in the Figure, the original light beam 3 has now been deflected to one of paths 101, 103, or 107, depending on the energization of electro-optic crystals and 112. The selected light beam, after passing through electro-optic crystal 114, can be further deflected by birefringent crystal 104 and further deflector stages comprising electro-optic crystals 116 and 118 and birefringent crystals 106 and 108. As shown in FIG. 3, the light beam can emerge along any one of the paths shown at 130. In the example described any one of 32 different character areas of matrix strip can be selectively illuminated by the light beam depending on the energization of the light deflectors. If desired, the mirror arrangements utilized for limiting the size of birefringent crystals can be replaced by the prism system shown in FIG. 4, in which two prisms 134 and 136 accomplish the same function as a mirror array such as 128-123 and 127.

The array of FIG. 3 is represented in FIG. 1 by box 6. In this Figure, in a preferred embodiment of the invention there are disclosed a plurality of light sources and light directors, a second deflector 8 being shown in FIG. 1 for purposes of illustration. This arrangement makes it possible to significantly limit-the size of light deflecting crystals.

The coarse character selecting the spacing mechanism shown as box 16 in FIG. 1 is represented in more detail in FIG. 2. In this Figure the matrix strip is shown adjacent to the entrance of the coarse deflector although it is actually beyond the beam merging prisms 1244 of FIG. 1. As mentioned above, in the example shown the matrix strip is provided with 32 characters a, b, c 3, 4, 5. The character-bearing light beam entering the coarse deflection system can be directed to any one of 64 different positions by selectively energizing electro-optic plates 148, 150, 152, 154, 156 and 158 associated with birefringent crystals 149, 151, 153, 155, 157 and 159. In the example shown, the thickness of these crystals vary as a power of two so that a deflecting unit with six elements produces 64 possible deflections. However, the use of a binary arrangement is not required. In addition, in a preferred embodiment of the invention the high-order stages of the deflector (those producing the maximum deflection) are replaced by a system that will be described hereinafter with a view to limiting the thickness of birefringent crystals and thus avoiding the problems associated with crystals of relatively large thickness.

As seen in FIG. 2, the first character a of the matrix strip 140 can be projected to any one of 64 positions between points 161 and 162 at the exit plane of the last crystal 159 of the deflector. Similarly, the last character 5 of the strip, entering the system along path 164 can be projected to any one of 64 positions between points 165 and 166. According to a characteristic of the invention, the projection zone represented by shaded position 138 is the only one utilized. This zone is comprised between the ray representing the straight projection (zero deflection) of the first character of the strip and the ray representing the maximum deflection of the last character of the strip, plus allowance for the maximum character width. In the example of the Figure, there are 24 coarse character positions in this zone, each separated by 16 relative units. The selection of the deflection stages to be operated to project a character to the proper coarse location is determined by the character rank and the accumulated widths of the characters of the line, as will be explained later.

, The selected character beam emerging from crystal 159 is further deflected by deflecting block 144 for fine positioning on the film (or other photoreceptor). The block 144 can deflect a light beam to any one of 16 positions (including zero) one relative width unit apart from each other. Block 144 can, if desired, compromise several deflecting stages similar to those utilized for the coarse selection, or can compromise a crystal (or multiplicity of crystals) capable of deflecting a beam in proportion to an applied electrical field, or any'equivalent device as known in the art. The use of such an analog defection is possible in the system described because of the small deviation of light beams required for the fine positioning of characters.

Emerging from block 144, on its face 169 is a line of character images of different widths. In a preferred embodiment, this line does not exceed 388 relative units (including the width of the last character), representing 40 characters of average width. This figure is convenient in that the line is sufficiently short to limit the size of the fine deflector, and yet is sufficiently long to represent the width of any standard newspaper column. The line of characters emerging from face 169 of deflector 144 is further referred to as a line segment.

Next, the character images of line segment 146 enter the line segment positioning section of the machine, as shown in FIG. 1. In order to avoid the use of impractically thick birefringent crystals for the positioning of line segments on the film, the below-described light deviation system is utilized. This system uses a relatively small birefringent crystal (associated with an electrooptic crystal) to deflect the light beam in a plane perpendicular to the plane in which a large deflection is desired, said small crystal being associated with light deflecting surfaces spaced apart in proportion to the deflection desired and further associated with another crystal to return the beams to their original plane.

The pictorial representation of FIG. 8 illustrates the operation of this system. Light beam 88 enters birefringent crystal 42 and emerges either at 90 or 92 depending on its polarization. One light beam emerging along path 90 will pass over mirror 32 to impinge on mirror 34 from which it is deflected toward birefringent crystal 44 (of the same thickness as crystal 42) which deflects beam 90 along line 96, preferably on the same level (i.e., distance from plane 49 on which the crystals are sitting) as entering beam 88. An undeviated (ordinary) beam emerging along path 92 from crystal 42 is deflected by mirror 32 to pass undeviated through crystal 44, emerging along path 94. It can be seen that the total deviation HD of the light beam entering the system does not depend on the thickness of a crystal,

but on the relative position of the reflecting surfaces 32 and 34. It is apparent that this deviation can be made as large as desired.

The components of FIG. 8 are also shown in FIG. 1, which shows the electro-optic crystal 144 being utilized to change the polarization of the selected beam if required. As shown in FIG. 1, the character-bearing beam entering the line segment deflection system is located in area 56, in the plane of the Figure and at a distance from line 45 (representing the path of the first character of the line segment) dependent on the deflection produced by blocks 16 and 144. The beam polarization can be changed by electro-optic crystal 40 so that the emerging beam from crystal 42 hits either mirror 32 or mirror 34 in order to enter crystal 44 in area 58 or 60. The deflector system which consists of electro-optic crystal 48, vertical deflector 46, mirrors 36 and 38 and repositioning crystal 63 is similar to the one just described. Thus, it is apparent that line segment 56 can emerge from the last crystal at 68, 70, 72

or 74 to produce a line four times as long as the original lines segment. The character-bearing beams are further deflected by a lens system 64 to produce character images of different sizes, as will be explained later.

It should be pointed out that the use of characters aligned along a single line on the matrix makes it possible to reduce the size of the crystals, as is apparent in FIG. 7, which is a cross-sectional view along line a-b of FIG. 1. The size of the deflection system can also be minimized by the use of master characters of small sizes. In one embodiment of the machine a matrix strip contains 64 four-point characters in a row, each spaced 20 width units apart. A four-point character area is approximately 1.6 X l.6 millimeters, and a line segment will thus be limited to 388 units, or approximately 31 millimeters.

In the alternative of FIGS. 6 and 9, the line segment is positioned on the film by the use of a series of mirrors 22, 24, 26 and 28. These mirrors may be movable up and down (perpendicular to the plane of the drawing) as explained in U.S. Pat. No. 2,946,268, in order to intercept the character-bearing light beam. Or, if desired, they could remain stationary and have partially reflecting surfaces. In this case the line segment 56 is partially deflected to locations 82, 84 and 86 (see FIG. 9) and the desired reflected segment can be selected by the use of a deflection system comprising a group of electro-optic crystals 76, birefringent crystal 78 and reflector 80. The unwanted segments are projected outside of the system by deflecting them as shown in FIG. 10 and projecting them to a light absorbing box 81.

The character selection and positioning control will now be explained by a specific example. As explained in U.S. Pat. No. 3,188,929 each character of the matrix is assigned a rank value representing the distance, in width units, of said character from an arbitrary reference point preferably at one end of the matrix strip. With characters spaced 20 units apart their rank value will be as shown in FIG. 15. The displacement value of a character of a line is obtained by adding its rank value to'the accumulated widths of previous (or following) characters of the line. The table of FIG. 16 v shows the accumulated width of the characters of the line Photon, Inc.. The individual width in relative units of each of the characters of these two words is shown in the second column, the accumulated widths in the third column and the displacement value in the fifth column. The displacement value, as in U.S. Pat. No. 3,188,929, represents the number of units by which a light beam emerging from a character area must be displaced in order to reach the film at the desired location in a line of composition. In the U.S. Pat. No. 3,188,929 the image is displaced by optical means (e.g. a moving lens) whereas in the present example the displacement is obtained by deflecting means. In the example shown, the coarse positioning and selecting means comprise six binary stages (FIG. 2). The stages to be energized are represented by columns S to S of FIG. 16. Column S represents a 16-unit deflection, a column S a 32-unit deflection, column 8;, a 64-unit deflection, etc. The following column represents the fine deflection in units. The column thereafter represents the line segment involved in the composition of the line. In this particularexample, only one line segment is involved because there is no accumulated width value higher than 370 units. The last column represents the flash position of the respective characters on the matrix. The asterisks adjacent to the numerals l6 and 9 indicate that the respective characters are located in the upper-case segment of the matrix. It is further assumed, in this example, that the characters are projected onto the film without changing their size. In general (except for the production of four-point lines) the character images produced on the film will be of a larger point size.

The use of a light source producing highly collimated light associated with deflecting means that do not change the orientation of the light rays produced means that all the character-bearing rays emerging from crystal 62 are parallel to each other. Thus, magnification can be obtained by the use of a diverging lens 64 sufficiently long to receive all the rays emerging from crystal 62. Also, because of the small height (perpendicular to the plane of the drawing) of characterbearing light beams, the lens can be reduced to a narrow strip 244 as shown in FIG. 11. It is thus possible to position a relatively large number of lens strips of different focal lengths in a small space, and therefore speed up the point-size changing operation because of the small mechanical displacement required to move from one lens strip to another.

In one embodiment, lens strips of varying focal lengths are located on a lens turret 233 (FIG. 12) that can be indexed around a shaft 235. Representative lens strips are shown at 236, 238 and 240. A schematic representation of a portion of this lens turret is also shown in FIG. 14 with lens strips represented at 234, 236, 238, 240 and 242. These strips can be located in grooves as shown, but accurate positioning mechanisms (not shown) are generally required for good alignment of characters of different sizes on the film.

The system shown in FIG. 13 could be used for extremely fast size-changing. In this Figure, lens strips are shown at 236, 238, 240 and 242. They are at a fixed position at the output face of a light deflection block 248. This block could include two binary" stages of crystal deflectors that would permit the entering character-bearing light beams to be deflected to the selected lens strip. The rays emerging from the lens strip can be returned to a common path by the use of another deflecting block, or a base line correction can be achieved by moving the film up or down as explained in detail in copending application U.S. Ser. N 0. 827,128 filed May 21,1969.

The output of crystal 62 (FIG. 1) may comprise four line segments 68, 70, 72 and 74 as shown also in FIG. 18. In this Figure two lenses of different focal lengths are schematically represented at 294 and 296. Since these lenses are receiving parallel or collimated bundles of light, they can be located at any distance from the system. In a preferred arrangement, as shown in FIG. 18, the magnifying lenses have their optical axis (0-0) on the centerline of the array of line segments, that is, between segments and 72 in the Figure.

As explained in co-pending application Ser. No. 827,128, the retention of a common left hand margin of the text on the film for different sizes requires a shift toward the centerline of the pre-magnification line (or line segment). This is illustrated in FIG. 18. In this Figure, the film plane is shown at 264 and the useful film area at 66. The maximum length of line is represented by J, with the left hand margin of the text at 274 and the right hand margin of a line of maximum length at 278. The focal length of lens 294 and its distance to film plane 264 are such that an order of magnification of six is obtained; that is, for four-point matrix characters the lens will produce 24-point characters. As can be seen in the Figure, lens 294 will project the left hand extremity 270 of the first line segment 68 at point 271 on the film plane and the right hand end 272 of line segment 74 at point 273. It is apparent that these two points are well outside the useful film area 66.

In order to project the first 24-point character flush with the left hand margin at point 274, it is necessary to displace (or delay) the projection of the first character from point 270 to point 281, located at a distance DA from point 270. This point 281 is located at a distance from opticalaxis 0--0 equal to the distance from point 274 (left hand margin of film) to said optical axis di vided by the magnification ratio. Another lens of lesser magnification, such as 296 (magnification ratio of 5/4) will project the point 270 at 274, on the left hand margin. This lens will produce five-point characters, which, in this example, is the smallest point size that the machine can produce in lines of maximum length I. It is clear from the above description that high magnification lenses do not have to be as long as the length of line segment C. For example, the 24-point lens 294 can be limited to the length shown as a solid line, as this is sufficient to cover the useful area of C and thus the longest line I permissible on the film. It is also possible to change size by changing the relative distance between the character presentation plane 270-272 and the image plane 274-278, as is schematically shown at 299 in FIG. 18.

According to another aspect of the invention lines of different sizes are automatically positioned flush with the same margin, basically as explained in copending application Ser. No. 827,128 filed May 21 1969. FIGS. 19., 20, 21 and 22 of the present invention are similar to FIGS. 13, 11, 14 and 12 respectively of Ser. No. 827,128, the same reference numbers referring to similar components. FIGS. 19 and 21 are given by way of illustration only, and it must be understood that the enlargement system of FIG. 18 is usually preferred. In FIGS. 19 and 21, it is assumed that the light rays emerging from the last crystal of the deflection system are directed toward a magnifying lens (part of a lens turret) 275. This can be achieved by the use of a condensing lens or the like at the exit of the last crystal, but this is not critical, since the only purpose of FIGS. 19 and 21 is to clarify the operation of the system.

As explained in Ser. No. 827,128, C represents the line of characters as flashed, beforemagnification, with points 270 and 272 representing the extremities of said line. The film 66, like the line C, is centered on the optical axis 39. J represents the maximum length of line that can be obtain in the present example. Enlarging lens 275 projects point 270 at 271. In order to bring this point to position 274, representing the left hand margin of the text, it is necessary to shift the location of the first character of the line, before enlargement takes place, from 270 to 281, by a distance DA (see FIG. 19). As explained in Ser. No. 827,128, DA=CI2 J/2E when C is the maximum length of the character-bearing light bundles entering the magnification system, J represents the maximum length of line after enlargement, and E is the enlargement ratio. C/2 is a fixed value which in the present example is equal to two line segments (as defined above) or 740 units (of four-point type). In the present example, J has been chosen to be equal to 1,840 units (of four points). With four-point master characters on the matrix, E=S/4, S representing the desired point size. So, again for this particular example, DA=740 3680/S.

FIG. 20 shows how the correction for margin shift due to magnification can be automatically carried out. Block 246 represents the storage register of the machine that contains all the necessary information for the composition of at least a line of text. Whenever block 246 reads and recognizes a point size shift code, this code is transferred via wire 303 to point size storage 304 until a new point size is entered. The value stored in block 304 is the value represented by S in the above formula. This value is transferred via wire 305 to a divider 306, where it is divided by a constant value K stored in block 308. K is equal to one-half of the maximum length of line, multiplied by the matrix character size. The result of the division stored in block 306 may not be an integral number, in which case the decimal value can be ignored. The result of the division is transferred via wire 309 to subtractor 310 to be subtracted from value K stored in block 312. The result isnext transferred over wire 314 to register 315. It is then added to the accumulated width value of characters as will be explained later.

FIG. 21 is similar to FIG. 19 and schematically represents a way in which characters, words, or lines can be automatically centered on the optical axis 39. As the system operates basically as described in Ser. No. 827,128 in relation with FIGS. 11 and 12 of said application (said Figures having identical reference numbers), the explanation given in the specification of Ser. No. 827,128 will not be repeated.

An example illustrating the automatic positioning of line segments to produce a continuous line will be given in relation to FIGS. 29 and 30. In FIG. 29, three line segments 68, 70, and 72 are shown as they emerge from the selective positioning system before magnification (see also FIG. 1). Each one measures (from the reference line of the first character to the reference line of the last character) not more than 370 units. However, characters can extend beyond the right hand margin of each segment by a number of units equal to the widest character of the alphabet, i.e., 18 units, as shown in the Figure. In the example shown, a line consisting of the letter M is to be composed, said character being l8-units wide.

Referring now to group 301 of FIG. 30, the sequence of characters is shown in the first column, the accumulated widths in the second column, the line segment used in the fourth column, and the displacement value in the fifth column. The displacement value for each character to be projected is obtained by adding the rank value and accumulated width of the character. The displacement value determines the location of the various characters in the line being composed. Characters are pulled out of storage one after another and their width added until the accumulated width becomes larger than 370 units (maximum segment length). At this point, 370 units are subtracted, the first segment is terminated and the second segment started by flashing the first character with a displacement equal to the amount carried over from the subtraction. As an alternative, the selection of a line segment can be obtained by pre-filling the accumulator by a value equal to its total capacity minus 370 so that a carry from the accumulator will shift the deflection circuit from one segment to the next.

In the example of FIGS. 29 and 30, it will be seen that there will be 21 Ms in the first line segment, because the 22nd M would cause the accumulated width value to exceed 370. The second line segment will start with the 22nd M, with 8' units left over from the first segment. The second segment will terminate with the 42nd M and the third segment will start with the 43rd M and 16 units carried over from the preceding segment. These segments are shown in a staggered manner in FIG. 29 for more clarity and it can be seen in this Figure that the S-units carried over from the first to the second segment cause the second segment to start 8 units from its usual margin. Similarly, the first character of the third segment will be projected at 16 units from its left hand margin as shown.

The automatic margin compensation for different magnification ratios will now be explained relative to FIGS. 30 and 31. Section 30-2 of FIGS. 30 represents the values associated with the projection of a line of 8- point Ms and section 30-3 with a line of 24-point Ms. Applying the margin correction formula described above (and in copending Ser. No. 827,128) it can be seen that the correction for 8-point type or a 2/1 magnification equals 280 units and for 24-point characters it equals 587 units (in round Figures).

As shown in section 30-2, the margin correction Figure is added to the accumulated width Figure until the added Figures exceed 370. This point is reached with the seventh M of the sequence. As explained above, the values in excess of 370 causes the termination of a line segment and the beginning of a new one. It can be seen in the Figure that the first line segment terminates with the sixth character and the second segment starts with the seventh character and zero units carried over, because the accumulated width of the sixth M plus the margin correction happens to be exactly 370. The second segment ends with the 27th character and the third segment begins with the 28th character and 8 units carried over.

Group 30-3 of FIG. 30 represents the sequential values for the projection of a line of 24-point Ms. Once again, in this case, one would start by adding the margin correction factor which equals 587 units, to the first character. Since this Figure exceeds 370, the value 370 is subtracted from 587, leaving 217 and the first segment is by-passed. The fact that this first segment will not be used is clearly illustrated in FIG. 18, in which it can be seen that the correction DA moves the first character to be projected from point 270 to point 281, well beyond the limits of the first segment 68. The distance from the left hand extremity of segment 70 to point 281 is equal to 217 units which will be added to the accumulated widths of characters of the second segment, as illustrated in FIG. 30-3. It can be seen that nine characters will be projected before the value of column 3 in group 30-3 exceeds 370. At this point the second segment will be started with 9 units carried over from the first.

A circuit capable of implementing the system just described is shown in the block diagram of FIG. 31. In this diagram, block 355 represents the line storage and main circuitry used to control the operation of the machine. Character identity codes are removed one by one from storage to box 356 where they can be decoded and alphanumeric character codes separated from function codes. The width of each character to be flashed is stored in box 359 and, under the control of each character code, the corresponding width is entered into accumulator 360. Accumulator 360 is also receiving the justifying interword space widths from the justifying space storage. In addition, accumulator 360 receives, from block 361, the margin correction value, either computed as explained above or pre-computed and stored in a storage unit from which it is extracted in accordance with the point size (magnification) selected, as stored, for example, in box 355.

The margin correction, as shown in earlier examples, is used only with the first segment to be projected. Thus, box 361 can be reset by the line segment control 366 as shown. The value accumulated is box 360 is continuously compared, in comparator 362, with the maximum length of a line segment. As explained above, whenever the accumulated width values exceeds 370,

I the difference is returned to the accumulator and the line segment control 366 shifts the line segment deflection system from one segment to the next. Of course, in the example shown in relation to FIG. 30, the segment shift is made before the character that causes the accumulator to exceed 370 is completely processed and flashed, because in the example shown above, said character belongs to the following line segment. The values emerging from accumulator 360, decreased by n times 370, are directed to adder 364 where said values are increased by the rank value of characters as stored in box 363, so that the displacement value of each character is successively obtained in order to be stored in box 367. Box 367 controls the coarse deflection circuit 368 and the fine deflection circuit 369.

' the light deflector 357 associated with the light source to be deflected so that it illuminates the selected matrix character (see FIG. 3). Next, after a given delay, the flash control circuit of box 358 is energized to cause a flash to occur and project the selected character. As can be seen, the following operations have taken place before the flash occurs: removing a character from storage, selecting a line segment, selecting the total deflection value associated with said character, and selecting the location to be illuminated on the matrix. The flash control circuit could includemeans to vary the exposure time in accordance with the point size of the characters to be projected and also with the type face desired, since it has been found by experience that bold type faces require substantially less exposure time than light type faces.

In the case where the fine segment deflector includes a series of mirrors as shown in FIG. 9, there is generally a gap between the areas 82, 84 and 86 covered by each line segment, as shown in FIG. 17. In this case it is possible to use one lens (258, 260 and 262) for each line segment. Since it has been assumed that the optical system will always magnify the characters of the line segment, there will be an elimination of the intra-segment gaps (as shown in the Figure) where the length of line to be composed in plane 264 is shown at LL. The magnification of the segments cause the emerging light beams to spread. Thus, for line segment 258, the emerging light may extend from ray 317 to ray 318 for a large magnification, from ray 319 to 320 for a lesser magnification, and from ray 321 and 322 for the minimum magnification. Similar rays for extreme magnification are also shown for line segments 84 and 86.

It can be seen that certain areas of the film may be covered by light rays emerging from one segment or another. For example, for minimum magnification, the shaded area is common to two adjacent partially overlapping segments. The computer associated with the machine can determine, for any given point size, the accumulated widths (including corrections) of characters of one segment and select the best segment to be used. In most cases, there will be an optimum choice of which segment to utilize in order to attain optimal optical conditions (i.e., as small a projection angle as possible because of lens limitations). Thus, for average and large magnifications, the central segment 260 only could be used. As can be seen, this segment, for an average magnification, is projected by light rays limited by rays 335 and 336 that cover the maximum length of line LL. This is also true of the larger magnification. The left hand margin correction is obtained as explained above.

FIG. 27 represents an array 10 of matrix strips of different type faces, 252, 253, 254 and 255 mounted in a frame 256 in such a way that the desired matrix can be pushed up to be inserted in the path of the illuminating device, as illustrated by the position of matrix 253. The fact that matrix strips appear at different locations between the illumination and the deflecting system is of no importance in a system using highly collimated light as a source of illumination.

Another form of the invention will now be described in relation to FIGS. 23, 24 and 25. In these Figures, the matrix shown at 174 (FIG. 25) is a continuously moving strip, for example, as shown in U.S. Pat. No. 3,291,015. This strip can be mounted on a continuously rotating drum as shown at 175 (FIG. 23) and described in U.S. Pat. No. 3,422,736. The principle of operation is schematically shown in FIG. 23. In this Figure, block 195 represents an illumination system capable of producing flashes of extremely short duration. The system may include a laser. Block 188 is a light deflector similar to the light deflector of FIG. 3 described above. This light deflector can selectively illuminate a pre-selected area on the matrix in a manner such as is explained in U.S. Pat. No. 3,416,420. These areas should be at least as large as the largest character of the matrix and they can, if desired be located 8 units apart so that the system operates basically as described in U.S. Pat. No. 3,422,736. As explained in this patent, the exact timing and positioning of the flash within a certain area 340 controls the fine positioning of the characters on the film. Area 340 can be made large enough to cover, for example, 128 units. The coarse character positioning is obtained by a series of light deflectors schematically shown in the form of light switches or crystals 226 and mirrors such as 230. Projection area 340 is similar to a line segment as heretofore explained, and can be positioned at location 232 and the adjacent locations, as shown, depending on the number of light deflector stages. In the case where a matrix strip or band continuously moving along a straight line utilized, it is possible to add other exposure stations such as shown at 197, 190, etc.

In the more detailed representation of the deflecting system shown in FIG. 25, the line segment 176 can be projected through a two-stage binary deflector to four different locations on the film. The deflector shown operates in the same manner as the deflector of FIG. 1, and like components are represented by identical reference numbers. FIG. 24 represents schematically the juxtaposition of two deflecting systems of the type shown in FIG. 25 in connection with two adjacent projection areas associated with projectors 188 and 190 respectively.

The system comprising a moving matrix operates basically as explained in U.S. Pat. Nos. 3,422,736 and 3,512,562, except that characters are projected to any area of the film by instantaneous deflectionof the character-bearing light rays, rather than progressively. It is evident that a certain delay will be required following each flash, in order to take into account recharging time for the flashing circuit. In the meantime the desired character could pass through the projection area; thus, another machine cycle will be necessary to project this character. However, the number of times the matrix strip should cross the projection zone to produce a line can be minimized by repeating, along the matrix strip, the most frequently used characters. It is also possible to use more than one light source as schematically shown in FIG. 26. In this Figure, four independent light sources are shown at 198, 199, 200 and 201. Any of them can reach the central deflector 208 by energization of the appropriate light switches or crystal 202, 203 or 204. The deflector 208 can be similar to the one illustrated in FIG. 3. The rays emerging from deflector 208 are directed by light switches 205, 206 and 207 to locations 209, 210, 211 and 212 which can represent the central point of several exposure areas, such as area 340 of FIG. 23.

The moving matrix system can be further modified to move an image of the matrix characters rather than the characters themselves. Such an arrangement is shown in FIG. 32, including a movable carriage provided with mirrors 214 and 216 which can slide along matrix strip 174, for example, to position 2l4-2l6'. A fixed mirror 218 can be used to direct the emerging light beams 222 to the selection and positioning system.

It is usually desirable to adjust the amount of white space located between adjacent characters for large magnifications by amounts depending on the type face design. This could be accomplished as shown schematically in FIG. 28. In this Figure, the point size information, stored in block 324 cooperates with the type face information of block 326 to generate via block 328 the stored correction factor which is to be subtracted by subtractor 329 from the accumulated width shown in block 330, in order to control the spacing circuits shown at 332. The exposure control 334 can also be modified by the use of stored values to accommodate different magnification ratios and different styles.

Although the invention has been more particularly described for sequential projection of characters, it is evident that in the example of FIG. 23 the first character entering the projection zone will be the first projected, regardless of its position in the line. The system described in relation to FIG. 1 can also operate in a non-sequential manner. For example, the deflection means can beoperated in a continuous selective fashion to cause a potential image of the matrix strip to sweep across the width of the film as explained in U.S. Pat. Nos. 3,188,929 and 3,416,420.

Although the invention has been described in relation to the use of birefringent crystals, other analogous light deflecting means could be used, particularly relative to the mirror deflectors of FIGS. 3 and 8 in whicha small deflection angle can be amplified as required.

The foregoing description is intended to be illustrative only. Various changes or modifications in the disclosed embodiments may occur to those skilled in the art. It is understood, therefore, that all such modifications as would be apparent to one skilled in the art are included within the scope of the present invention.

What is claimed is:

1. A composing machine comprising:

a character matrix having a complete alphanumeric array aligned along a single line thereon,

means for providing a beam of collimated, planepolarized light,

a light-sensitive surface for receiving said light beam,

and

instantaneous deflection means for selecting a character and directing it to any one of a plurality of locations parallel only to the base line of a line under composition on said light-sensitive surface in order to form a line of composition thereon,said instantaneous deflection means including means for taking into account, the accumulated widths of the characters which have previously been directed to said line of composition, and the position of the character which is to be selected along said single alphanumeric line of the character matrix.

2. The machine of claim 1 in which said instantaneous deflection character selection means includes a plurality of birefringent crystals spaced from one 

1. A composing machine comprising: a character matrix having a complete alphanumeric array aligned along a single line thereon, means for providing a beam of collimated, plane-polarized light, a light-sensitive surface for receiving said light beam, and instantaneous deflection means for selecting a character and directing it to any one of a plurality of locations parallel only to the base line of a line under composition on said light-sensitive surface in order to form a line of composition thereon, said instantaneous deflection means including means for taking into account, the accumulated widths of the characters which have previously been directed to said line of composition, and the position of the character which is to be selected along said single alphanumeric line of the character matrix.
 1. A composing machine comprising: a character matrix having a complete alphanumeric array aligned along a single line thereon, means for providing a beam of collimated, plane-polarized light, a light-sensitive surface for receiving said light beam, and instantaneous deflection means for selecting a character and directing it to any one of a plurality of locations parallel only to the base line of a line under composition on said light-sensitive surface in order to form a line of composition thereon, said instantaneous deflection means including means for taking into account, the accumulated widths of the characters which have previously been directed to said line of composition, and the position of the character which is to be selected along said single alphanumeric line of the character matrix.
 2. The machine of claim 1 in which said instantaneous deflection character selection means includes a plurality of birefringent crystals spaced from one another, each of said birefringent crystals having an electro-optic device associated therewith, in order to form a plurality of crystal deflectors, and further includes a movable optical reflector means located in the space between at least two of said crystal deflectors such that a collimated light beam may be deflected to any one of the characters in said alphanumeric array for the purpose of illuminating a character which has been selected.
 3. The machine of claim 1 in which: said character matrix is rotatable, said instantaneous deflection means for character selection includes fine positioning means for locating said light beam at any one of a plurality of positions along a projection area adjacent to said matrix such that a selected character may be illuminated at any given time during its passage through the projection area, in order to variably position said illuminated character at any point within a predetermined segment of the line to be composed, and said instantaneous deflection means for character direction includes coarse positioning means for directing said predetermined segment of characters to any one of a plurality of locations along said line to be composed in order to properly position or space said characters along said line.
 4. The machine of claim 1 including means for changing the point size of said selected, directed characters, said size-changing means being positioned in the optical path between said deflection means and the light-sensitive surface such that said characters are spaced from one another on said surface by optical leverage without taking into account their point size.
 5. The machine of claim 4 in which said instantaneous deflection means includes means for automatically positioning lines of composition of different point sizes flush with the same margin, said positioning means compriSing: means for storing the point-size or magnification ratio of the characters of a given line to be composed, means for storing the rank value of the first character of said line, and means for generating and storing a margin correction value based upon inputs from said point size and rank value storage means, said margin correction value including means for selectively controlling a plurality of deflection stages in order to properly position the first character of said line flush with the margin of said surface.
 6. The machine of claim 4 in which said instantaneous deflection means includes means for centering the line to be composed on the optical axis after the point size is changed, said centering means comprising: means for storing the point size of the characters of a given line to be composed, means for storing the displacement value of each character of said line, and means for generating and storing a line centering correction value based upon inputs from said point size and displacement value storage means, said centering correction value, including means for selectively controlling a plurality of deflection stages in order to center said line on the optical axis of said machine at said surface.
 7. The machine of claim 1 in which said instantaneous deflection means includes a white space reduction circuit for adjusting the amount of space between adjacent characters in accordance with the particular type face and point size in use, said circuit comprising: means for storing point size information for said characters, means for storing type face information for said characters, means for generating and storing a correction factor or value based upon inputs from said point size and type face storage means, and means for subtracting said correction factor from the stored accumulated widths of the preceding characters in order to control a character spacing circuit for the purpose of properly spacing said characters from one another along a line of composition.
 8. The machine of claim 7 in which a light-beam exposure control is adapted to receive inputs from said correction means in order to enable said control to accomodate various point sizes and type faces.
 9. A composing machine comprising: a character matrix having a plurality of characters arrayed thereon, means for providing a beam of collimated, plane-polarized light for illuminating a selected character, a light-sensitive surface for receiving a character-bearing light beam, a first crystal deflector for deflecting a pre-selected character-bearing light beam in a direction perpendicular to a line of composition which is to be formed on said light-sensitive surface, said first deflector having a plurality of movable optical reflectors associated therewith, said optical reflectors being spaced from one another by a distance which is proportional to the desired amount of deflection of said light beam along said line to be composed, and a second crystal deflector positioned in the optical path between said reflectors and said light-sensitive surface for the purpose of returning or re-deflecting said light beams to its original direction in order to form a line of composition on said light-sensitive surface, said second deflector having the same thickness as said first deflector.
 10. The machine of claim 9 in which: said first and second deflectors each comprise a birefringent crystal having an electro-optic device associated therewith, and said optical reflectors comprise a pair of mirrors, one of which is positioned so as to reflect the ordinary ray of said light beam, to the second deflector the other mirror positioned so as to reflect the extraordinary ray of the light beam to the second deflector.
 11. In a light-deflection system: means for providing a beam of collimated, plane-polarized light in a first orientation, a light-sensitive surface for receiving a light beam, a first electrically-coNtrolled light-deflecting crystal for deflecting said light beam in a direction perpendicular to said first orientation, said first crystal having a plurality of movable optical reflectors associated therewith, said optical reflectors adapted to be spaced from one another by a distance which is proportional to a desired amount of deflection of said light beam on said light-sensitive surface, and a second electrically-controlled light-deflecting crystal positioned in the optical path between said reflectors and said surface for the purpose of returning or re-deflecting said beam to its first orientation in order to deflect said beam by a desired, pre-determined amount on said surface, said second crystal having the same thickness as said first crystal. 